Study On Piezoelectric Thin Film Micro-pump For Micro Fluidic Chip

Micro fluidic systems are important elements of a micro total analysis or a lab-on-a-chip. It is on the basis of MEMS technology, using micro channels net as structure characteristic, achieve the fluid manipulate and control by micro pumps and micro valves , which aims to perform all kinds of operations, such as sample introduction, pretreatment, reaction, separation and detection operating and can use many times. Since it has more automatic level and more abroad applicability. Micropump is the core components of the micro fluidic sysmtem, which can realize the micro flux to control and output. So it has abroad applicability .In this dissertation, circle piezoelectric flim and plannar micro pump as well as micro fluidic chip intergred miro pump are introuced. Circle piezoelectric film and plannar micro pump are prepared and its structure are optimized. In order to realize the lab -on -chip applicability aims, the micro pump , as a device for automatic sample exchanging and washing , is integrated to the micro fluidic chip. The works carried out can be mainly summarized as follows:(1) Preparation of circle piezoelectric flim and its structure optimization. In this dissertation, the process of PZT thin films prepared by hydrothermal method .To prepare circle piezoelectric thin film with good performance and adaptation to the micro-assembly , the relationships between the sizes of structure and its driving performance are simulated by Finite Element Analysis (FEA) software ANSYS. the mode analysis for the cirlce piezoelectric thin film is made to analysis the relationships between the frequency and accordingly shape change. Eventually, piezoelectric actuator with the best driving ability is prepared.(2) Piezoelectric valveless micro-pump theoretical analysis, prototype preparation and its structure optimization are studied. The working principle of the micro-pump and micro-pump fluid flow characteristics, which provides a theoretical basis for choice of micro-pump basic parameters, is theoretically analyzed. The mutual influence between the solid and fluid field is considered by MFX-ANSYS/CFX technoloyg of ansys 10 edition, accordingly , the multi-physics field analysis of the valveless pump is realized , the fluid dynamic characteristics of the valveless pump are also researched. We also make use of the MFX-ANSYS/CFX technology to numerical simulations and get optimization paramaters of the angle, the mininal width, length of diffuser and the height of the chamber and get the optimize parameters. For validate the correctness of the simulation, we prepared the phtotype to reasearch the relationship between the driving voltage , working frequency and the flow rate.(3) The fabrication and performance testing of the micro fluidci chip with micro valveless pump is presented. the principle, structure design, manufacture, performance testing of this chip are presented. The system is sucessfully applied for automatic exchange sample and seperation of vatimin B2.